Nintendo announced that Crystal Version will be coming to 3DS on January 26, 2017, and will be priced at $9.99. Additional features will be added to the game as well.
Specifically, Crystal will be compatible with the Pokemon Bank, allowing players to carry over whatever they catch into the newer titles such as Ultra Sun and Ultra Moon. It will also allow for cross battle and trading with older versions, like Red, Blue, and Yellow, through a feature called Time Capsule.
Upon completing the game, players will have a chance to capture Celebi through an in-game event. This is in contrast to the original Pokemon Crystal, which required a special accessory called the Game Shark to cheat your way to obtaining this rare Pokemon.
Nintendo also states that with the release of Pokemon Crystal, it will now be possible to carry Pokemon from all 29 core games in the series over to Ultra Sun and Ultra Moon.